대퇴골두 무혈성 괴사에 속발된 대퇴경부 골절

Abstract

Avascular necrosis of the femoral head is usually a progressive condition. Segmental collapse frequently occurs in a femoral head affected with avascular necrosis during its progression. In a few ins- tanse, spontaneous subcapital fracture occurs more distally than the usual location of subchondral fracture. We reports 17 cases of femoral neck fracture following avascular necrosis of the femoral head. We histologically examined the head which had been removed during the operation. Preoperative radiographs, MRI and bone scanning were taken for the patients if possible. All hips revealed the bilateral avascular necrosis with total involvement of the femoral head. The femoral head fragments showed complete necrosis of the trabecular bone and marrow by postoperative histology . Among these cases, consecutive four cases were studied by macroscophic and microscophic histology to discuss the mechanism of these fractures. All 4 cases revealed the fracture line at the junction between the necrotic zone and the reparative zone. The presumed mechanism of this fracture is accumulated stress fracture at the reparative zone in the junction between the necrotic femoral head and normal neck.